Sleep apnea is a repetitive process of respiratory cessation. Results of on-going studies now show that one quarter of independently living people age 65 years and older have sleep apnea. It might be that sleep apnea is normal among the elderly, but sleep clinic studies suggest that an excess of this "normal" process may be disabling or fatal. Our data show that among representative subjects 65 years and older, sleep apnea is associated with excessive daytime sleepiness, confusional spells automatic behaviors, and depression. A disorder of leg jerks (periodic movements during sleep, PMS) is also found in 42% of our senior citizen sample. This study will examine morbidity and mortality of subjects with sleep apnea. Eight hundred veterans at the San Diego Veterans Administration Medical Center, 65 years of age or over, will be randomly selected for all-night portable respiration recordings. All-night oximetry will also be recorded. All subjects will be followed up over a 5-year period to determine the mortality rate for those with and without sleep apnea. In addition, medical data will be collected to determine conditions associated with the presence of sleep apnea. A second study will also be done as a follow-up of the senior volunteers whose sleep has been recorded in our present 1981-1985 study. This will be done to study longitudinally the co-morbid conditions developing with sleep apnea. These studies will determine the morbidity and mortality associated with sleep apnea in order to indicate the extent to which sleep apnea in aged patients needs treatment.